The initial 160 troops in what will be a 4,500-strong multinational force to keep the peace in the Afghan capital and surrounding areas deployed yesterday.

But they face formidable challenges, such as language barriers, no running water, and a city teeming with Northern Alliance troops. The agreement that brought peace to the country, brokered in Bonn barely a month ago, promised that the parties who participated in those talks would "withdraw all military units from Kabul and ... other areas in which the UN-mandated force is deployed."

But the Northern Alliance troops, whose leaders play key roles in the new, interim government, have not withdrawn from the city. And tensions are growing between Afghan and Western leaders over prolonged US airstrikes in the country.

One of the most important factors in bringing a sense of security was having an international peacekeeping force that would work alongside a united Afghan force, which would not be partial to military factions and would be recognized by all. Western negotiators in Bonn understood this to mean that Northern Alliance soldiers would be removed from the streets of Kabul. Afghan officials say they understood that literally: The Northern Alliance soldiers won't be on the street, but will be confined to barracks.

Though some British sources say that is a loophole to keep the Northern Alliance military apparatus in place, the official reaction is that it is the new Afghan leaderships' prerogative to change its mind.

"The Afghan interim administration are the sovereign holders of that agreement," says Simon Tonge, spokesman for the British Embassy in Kabul. Now that the UN-sanctioned ISAF and the Afghan administration have a military-technical agreement, however, arbitrary changes will be harder to make.

Britain, whose Royal Marines will lead the International Security Assistance Force (ISAF), says the Afghan interim government essentially reserved the right to interpret the Bonn deal as it saw fit. But the new peacekeepers also say some concepts the West had in mind for Afghanistan may be lost in translation. British officers keep mentioning the word "patrol," which doesn't exist in Dari, the dominant language in Kabul. And according to some reports, shortly after the Bonn accords were signed some soldiers simply painted their helmets to say "police" on them.

"There are clearly language differences, some very significant cultural differences, and we are going to have to work very hard to establish the effective partnership with the Afghan authorities," says Col. Richard Barrons, the chief of staff of the ISAF.

Relations between Afghanistan's new interim government and the leaders of the international community that helped create it are more at odds than a month ago. Some Afghan officials are increasingly critical of US airstrikes, especially after a bombing run on Sunday in the eastern province of Paktia reportedly killed more than 100 civilians.

In Washington, the Pentagon said that the target of the strikes was a base for Osama bin Laden's Al Qaeda network and its Taliban allies. A US military spokesman said strikes by two B-1B bombers and a B-52 destroyed a compound used by Al Qaeda and Taliban forces, adding that they were shot at by two surface-to-air missiles.

Another US bombing raid in Paktia province reportedly killed Qari Ahmadullah, the Taliban's chief of intelligence, late last week. The Monitor had interviewed Mr. Ahmadullah from a "guesthouse" near Afghanistan's border with Pakistan on Dec. 27. Ahmadullah is believed to be the highest official in the hard-line Taliban militia to be killed in the US-led campaign.

Meanwhile, the US and Afghan forces are intensifying their hunt for Mullah Mohammed Omar, the Taliban's leader, who is reportedly hiding out in Baghran, a mountainous region north of Kandahar.

The US sent 200 Special Operations troops in search of Mullah Omar Tuesday, while Afghan military leaders have been negotiating for two days with Baghran's loya jirga, or grand council of tribal leaders, for Omar's surrender.

But local tribal leaders and the country's interim defense minister, Mohammed Fahim, have demanded that the US bombing campaign end. Mr. Fahim says Mr. bin Laden has probably fled to Pakistan and that his fighters are too thinly dispersed and on the run to warrant continued bombing.

Fahim's criticism suggests key rifts in the interim government regarding the war on terror.

But Minister of Information and Culture Mahdoum says in an interview with the Monitor that he was sure the bombing in Paktia was an accident. "American targets are terrorist bases, and regardless of some of the mistakes that happen everywhere, their goal is to destroy terrorist bases in Afghanistan," he says. "If they destroy a civilian building, I'm sure it is by mistake."

The ISAF forces are being warmly welcomed by Afghans, who say they cannot see peace working without international help. But just setting up shop for the peacekeepers presents enormous logistical hurdles. The peacekeepers have to fly in their own food, water, generators, fuel, and virtually every other item needed to support their mission. The force is still scouting for empty buildings suitable to house the troops. In the meantime, the troops will be sleep in winterized tents.

"These buildings have been occupied on a gypsy-like basis, with fires in the rooms," says Colonel Barron, gesturing to a windowless, half-burned building that has housed a gamut of soldiers: the Taliban, the mujahideen before them, and Soviet soldiers before them.

"The real concern is power and light and water," says Maj. Gen. Rob Magowan, a planning officer with the Royal Marines.

But perhaps the greatest handicap for the ISAF is its "narrow air bridge." Kabul airport is just beginning to function, with the one commercial airplane that survived the war restarting domestic flights to Herat in western Afghanistan. There is at least one 500-pound bomb embedded on one taxi-way and one deeply embedded in the runway.

Demining continues, however, and an engineering officer says ISAF hopes to have the main runway cleared and open for traffic in 10 days.

Outside the main ISAF base, across the street from the recently reopened US Embassy, the average Kabuli does not know any foreign peacekeepers have arrived.

Yesterday, about 200 Afghan soldiers could be seen doing a modified goose-step into the Interior Ministry. They, and their equipment will have a significantly different look from the 17-nation ISAF, which doesn't include any US soldiers but has 30 US communications officers.